Symptoms and Causes of Dementia

Dementia is not a disease, but a term that covers a range of symptoms related to a decline in mental function. These symptoms can include memory loss as well as problems with reasoning, language, visual perception, and other cognitive functions. To be considered dementia, symptoms must be not in line with normal aging and severe enough to interfere with everyday life.

While there are several different kinds of dementia, most share similar symptoms:

Age is a prime factor in dementia—as people age, the likelihood they’ll develop the syndrome only rises. Many people attribute dementia to Alzheimer’s, but it’s important to know that it’s not the only cause. Here, we’ll explain the different types of dementia, what causes them, and what symptoms to pay attention to.

Alzheimer’s disease

Alzheimer’s disease is the most common form of dementia; up to an estimated 80 percent of people with dementia have Alzheimer’s. Alzheimer’s causes brain cells to be damaged and ultimately destroyed, leading to memory loss and reduced mental capacity. The cause of Alzheimer’s is not understood, and there is no cure.

While the disease’s progression doesn’t follow a predictable pattern, over time memory lapses and forgetfulness will get worse. People with Alzheimer’s often wander off, and they may experience depression or drastic personality changes. At its most severe, Alzheimer’s will impair a person’s ability to perform the most basic, everyday functions.

Lewy body dementia

Lewy body dementia, or LBD, is the second most common form of dementia and is related to abnormal protein deposits (composed mostly of the protein alpha-synuclein) that develop in several different regions of the brain. These deposits are known as Lewy bodies. In addition to a decline in cognitive function, people with LBD may experience hallucinations during early stages of the condition.

Because people with LBD can experience the same motor symptoms as someone with Parkinson’s disease (such as tremors, stiffness and walking problems), and because Lewy bodies can also be present in the brains of people with Parkinson’s, it can be difficult to distinguish between the two conditions. The order of symptoms can be a clue: People with LBD usually experience dementia first, followed by motor symptoms. For those with Parkinson’s, the motor symptoms precede the dementia.

Vascular dementia

A stroke is the most common cause of vascular dementia; when blood flow to the brain is blocked, brain cells can die, leading to impaired function. Other vascular diseases, like heart disease, can also limit blood flow to the brain over time, causing cognitive issues. Because strokes can affect different parts of the brain, symptoms will vary depending on the regions affected. In some cases, vascular dementia may not cause memory loss at first because those brain cells haven’t been affected.

Frontotemporal dementia

Frontotemporal dementia is triggered by the degeneration of nerve cells in the frontal and temporal lobes of the brain that are responsible for behavior and language; people with this type of dementia are also likely to experience personality changes. Most cases occur in people under the age of 65. Researchers still don’t understand what causes these cells to die.

Huntington’s disease or Parkinson’s disease

Both conditions are progressive neurological disorders that can also trigger dementia as the diseases progress. In addition to traditional dementia symptoms, people with these conditions experience involuntary shaking and deteriorating motor functions.